Canine lymphoma staging is done to help assess the progression of lymphoid cancer in dogs. These stages can determine whether the cancer is in its early stages, or whether it has progressed to an end-stage situation. With canine lymphoma staging, veterinarians are able to better assess a dog’s prognosis and which treatment options may be most effective.
Overview of Canine Lymphoma
In order to understand the various stages of canine lymphoma, it is important to first understand how this type of cancer works. Canine lymphoma is a form a cancer that primarily affects the lymph nodes. Although most lymph cancers start out affecting just one lymph node, this particular type of cancer is considered body-wide because it can metastasize, or spread, to any of the lymph nodes within the dog’s body. This makes canine lymphoma a particularly dangerous type of cancer.
The true cause of canine lymphoma is still not very well understood. The only proven factor for developing canine lymphoma seems to be a genetic tendency. Certain breeds, such as Golden Retrievers, have genetic predispositions towards developing lymphoma. The genetic code of this breed appears to have difficulty adjusting for damages to cells and DNA structure, which creates a higher likelihood of developing canine lymphoma.
Canine Lymphoma Stages
The levels of canine lymphoma are done on a scale of one to five:
- Stage I – cancer is localized to one lymph node
- Stage II – cancer is localized to two lymph nodes within the same region of the body
- Stage III – cancer has spread to several lymph nodes
- Stage IV – cancer has spread to all lymph nodes, the liver and the spleen
- Stage V – cancer has spread to the bone marrow
Because the symptoms of canine lymphoma occur over a period of time, most dogs are never diagnosed with stage I or stage II, typically because they are not brought in for medical evaluation until the cancer has reached stage III.
In order to accurately stage canine lymphoma, an array of testing will need to be done. An x-ray of the suspected area is likely to be the first diagnostic test performed. Once the presence of an abnormality is confirmed, the veterinarian will request that biopsies be performed. If just one or two lymph nodes appear to be affected, they will be the first to be biopsied. If these biopsies return a diagnosis of cancer, then the liver, spleen and bone marrow will also be biopsied so that the progression of the cancer can be identified and accurately staged.
It is important to note that not much medical evidence exists to support a definite prognosis at any of these levels. In fact, some dogs with stage III lymphoma have been less responsive to chemotherapy and more likely to go into remission than dogs at stage IV or V. The most accurate indicator seems to be how the dog is actually feeling at the time of diagnosis. Dogs that act and feel sick at the time of diagnosis typically do not respond as well to chemotherapy treatments.